Research on the Application of Linearization Pre-Distortion Technique for Memoryless Power Amplifier

2014 ◽  
Vol 687-691 ◽  
pp. 3521-3524
Author(s):  
Su Wang ◽  
Lang Zheng ◽  
Ze Ming Yang ◽  
Cai Zhong
Keyword(s):  
Power Amplifier ◽  
Nonlinear Problems ◽  
Error Vector Magnitude ◽  
Matlab Simulation ◽  
Distortion Model ◽  
Simulation Process ◽  
Input And Output ◽  
Output Amplitude ◽  
Amplifier Linearization ◽  
Vector Magnitude

In order to improve the nonlinear problems of power amplifier, this paper discussed about the nonlinear characteristic of power amplifier without memory and put forward a kind of new pre-distortion model. The MATLAB simulation process was being used to obtain the input and output amplitude curves, and calculated the normalized mean square error NMES and error vector magnitude EVM, the results show that the power amplifier linearization improved after pre-distortion processing.

Simulation on PAPR Suppression Algorithm for Multicarrier System

2014 ◽  
Vol 596 ◽  
pp. 794-798
Author(s):  
Rui Zhang ◽  
Zhi Bin Zeng
Keyword(s):  
Power Amplifier ◽  
Power Efficiency ◽  
Average Power ◽  
Power Ratio ◽  
Error Vector Magnitude ◽  
Crest Factor ◽  
Multicarrier System ◽  
Crest Factor Reduction ◽  
Small Distortion ◽  
Vector Magnitude

The main disadvantage of multicarrier system is the high peak-to-average power ratio which can easily result in significant cut-the-top distortion of power amplifier. However, the power efficiency of power amplifier will be reduced by power back-off technology. Therefore, crest factor reduction is important in reducing the peak-to-average power ratio of multicarrier system and improving the efficiency of power amplifier. The peak-to-average power ratio can be effectively reduced with small distortion by the algorithm of crest factor reduction based on peak cancellation. And the performance of peak-to-average power ratio is better with the same error vector magnitude.

scholarly journals Spectral Re-Growth Suppression in the FBMC-OQAM Signal Under the Non-linear Behavior of a Power Amplifier

2019 ◽  
Vol 9 (5) ◽  
pp. 4801-4807
Author(s):  
J. Jake ◽  
E. Mwangi ◽  
K. Langat
Keyword(s):  
Power Amplifier ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Nonlinear Behavior ◽  
Least Square ◽  
Error Vector Magnitude ◽  
Adaptation Algorithm ◽  
Error Vector ◽  
Adjacent Channel ◽  
Vector Magnitude

Typically, the filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) bears some impressive properties that make it popular as one of the substitutes to orthogonal frequency division multiplexing (OFDM) for the upcoming technology of broadband wireless communication systems. Although FBMC-OQAM preserves the multicarrier modulation (MCM) features, its spectrum usually suffers from impairments when subjected to the nonlinear behavior of a power amplifier (PA) which results in spectral re-growth. Due to the spectrum limitation and low energy efficiency foreseen in the forthcoming 5G networks, it is vital to confine the spectrum of the FBMC-OQAM signal within the allocated band of interest. In this paper, the suppression of the spectral re-growth experienced on the FBMC-OQAM signal due to the nonlinear distortion effects introduced by the PA is investigated. The crest factor reduction (CFR) method in combination with an adaptive digital pre-distortion (DPD) are used. The peak windowing technique based on sequential asymmetric superposition windowing (SASW) algorithm is used in the CFR part while the least square estimation with QR-decomposition (LSE/QR) has been used as the coefficient’s estimator and adaptation algorithm in the DPD part. The performance of the two combined techniques has been evaluated on SystemVue2018 simulation platform. The adjacent channel leakage ratio (ACLR) and the error vector magnitude (EVM) have been considered as the performance merits. The simulation results show that the proposed techniques significantly improve the spectrum, first by reducing the PAPR of the FBMC-OQAM signal by about 1.5dB. Secondly, the spectral re-growth has been reduced by about -45.74dB adjacent channel leakage suppression and the error vector magnitude measure has been obtained to be about 7.12%. (-22.95dB). These values lead to better average input power of the FBMC-OQAM signal and improvement in the spectral efficiency and they are in accordance with the 3GPP standard for wideband signals in nonlinear systems.

Sign in / Sign up

Export Citation Format

Share Document